Learning Forum

[Mn65]

Hello

I'm trying to model a pre-crack single lap bonded joint with the VCCT model and calculate the fracture energy at the crack tip.

When the analysis finish, this warning message appears:

"

[Sheldon Imaoka]

If you are trying to calculate fracture mechanics parameters, I am wondering why you have contact defined? In the crack front, there shouldn't be any contact for an open crack. Can you try this again after removing contact elements at the crack front?
Regards Sheldon

[Mn65]

Dear Sheldon,

 

Thank you very much for your reply. 

 

Could you consider the following problem? 

I have a question regarding the following problem that I'm trying to study in ANSYS Workbench. I'm simulating an adhesively bonded joint of a double cantilever beam  (DCB), and I'm trying to predict the load-displacement curve of this specimen. I did the following steps:

 

1- The experimental DCB tests were done and the load-displacement curves generated

2- The fracture toughness (G) of the adhesive was calculated with the analytical formulations

3- The same geometry was simulated in ANSYS Workbench (with the VCCT model) to create a FE model that could be able to predict the load-displacement curve of the experiment test (under the same loading conditions)

4- Then the FE model was modified by changing the mesh size and the value of G to reach the closest load-displacement curve to the experimental curve.

I have the following questions regarding this issue:

1- The following warning appears, what does it mean, and how I can solve it;

"The fracture parameters computed during solution may be incorrect. Check the Solver Output on the Solution Information object for possible causes"

2- Do you have any idea to improve my model to have a closer load-displacement curve with the experiment? The following image shows a comparison between FE and the experiment curve.

Thank you in advance for your consideration.

 

Regards,